How was the community in "The Giver" by Lois Lowry created?

This is an interesting question. As previously stated, the community is an intentional utopian community. It seems that the idea of family is one that is preserved from the past, but the idea of childbearing is one that is frowned upon as somehow lower class.

Everything is segregated into age groups. People wear a type of uniform that is related to their age when they are young or to their job when they are older. They take pills that remove their sex drive as well as their ability to see in color. They have gone to "sameness" meaning that there is a cookie-cutter idea of what people should be and do.

They have a 1:1 ratio of death to birth, and if twins are born, then the "better" one lives, and the "less able" one is "released".  Jonas witnesses his father releasing a twin by injecting a solution into the infant's heart. Jonas is mortified by what he sees, but his father simply accepts this as "normal". The word death is not used, but the word release is substituted for death. People determine when they will die and basically attend their own funeral prior to walking into the releasing room.

This community was created based on avoiding desires and cravings and by making sure that everyone is the same in every way possible. There is no pain, no discomfort, only sameness.  Career and work are valued, but having babies is seen as something that animals do.